Originally Posted by Anth Seebel
Yep thanks, IGP showing in device manager now. I have EIST and C3 enabled and working well.
Still it is more than just strange that the IGP should be enabled in order to get the EIST / C3 working without immediate crash.
Since you are using Asus board and I am using Gigabyte, It looks like the issue is related to Haswell architecture itself and not the motherboard.
Note that after a couple of days of fine tuning my OC, I figured out that C3 still causes random BSOD for my system on IDLE or low load like opening a folder or running utorrent.
It might happen in in 30 minutes / 4 hours / 10 hours.
Raising Vcore / Vrin / Ring / system agent / AIO while C3 enabled makes no difference - still random BSOD on near IDLE.
Though, Enabling EIST with C3 disabled looks rock stable with Multi drop and constant VCORE.
Any workaround to get stable vdrop with multi drop with OC ?